Thermally efficient connector system

ABSTRACT

A connector assembly can be provided. A receptacle includes terminals that can be positioned in a card slot on a 0.60 mm pitch (or greater). A biasing element can be provided in the card slot to engage a mating paddle card. The receptacle can be configured to allow air to flow from a front face to a rear face, the air passing through a middle wall. A plug assembly can be provided that includes a conductive body and is configured to generate some amount of heat. The body can include a surface that has cooling grooves. The cooling grooves allow air flow over the plug assembly so that the plug assembly can be cooled directly.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/109,862, filed Jul. 6, 2016, now U.S. Pat. No. 9,960,553, which is anational phase of PCT application Ser. No. PCT/US2015/022,705, filedMar. 26, 2015, which claims priority to U.S. Provisional Application No.61/971,366, filed Mar. 27, 2014, all of which are incorporated herein byreference in their entirety.

TECHNICAL FIELD

This disclosure relates to field of connectors, more specifically toconnectors suitable for supporting increasing needs for density.

DESCRIPTION OF RELATED ART

Input/Output (IO) connectors are well known. Some of the common typesinclude SFP, QSFP and CXP style connectors. One way these connectorstend to be used is a rack mounted switch so that a number of connectionscan be provided to other devices and high band width requirements can besupported. These connectors, while useful, tend to be configured toprovide terminals in a card slot at a 0.8 or 0.75 pitch. Each card slotcan have terminals on two sides of the card slot. Thus, the pitch theterminals are positioned on tends to limit the number of terminals thatbe provided in row and thus limits the bandwidth that can be supportedby a 1 U rack system. While IO connectors with small pitches are known,conventional IO connectors that use a paddle card in a plug connector(e.g., SFP, QSFP, CXP) are at 0.75 mm or larger pitch so as toaccommodate the tolerances inherent in the paddle card that is insertedinto the card slot (as the paddle card is typically formed with a PCBconstruction). Removing the paddle card could potentially help improvetolerance stack-up but the paddle card is desirable as it can supportcircuitry that allows the system to work, particularly for active copperand optical based plug assemblies.

It has been determined that when attempting to provide a card slot withterminal at 0.65 mm or less the tolerances of the circuit board that areused to form a paddle card become problematic if conventionalconstruction techniques are used. One approach to help resolve thisissue has been to use a biasing element in a cage that help bias theplug connector toward one side of a port. However, certain individualswould appreciate further improvements to a connector system.

In addition, existing systems tend to be difficult to cool, especiallyif the systems are arranged in a stacked configuration. Thus, certainindividuals would appreciate a connector system that could help addressthermal management issues.

SUMMARY

A connector is provided that has terminals in a card slot arranged in apitch of 0.6 mm-0.65 mm (e.g., between 0.59 and 0.66). A biasing memberis provided on one end of the card slot to provide sufficient tolerancecontrol. The connector can be configured so as to support active cableassemblies and optical modules (e.g., modules that create a thermalload) and in an embodiment can support modules that generate 2 watts ofpower. To provide cooling in a stacked configuration, air flow isdirected through the connector, over the module and out the back of theconnector so that the module can be cooled directly with air flowingthrough the system.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements and in which:

FIG. 1 illustrates a perspective view of an embodiment of a receptacleassembly mated to a plug assembly.

FIG. 2 illustrates a perspective view of the embodiment depicted in FIG.1 with one of the plug assemblies in an unmated state.

FIG. 3 illustrates another perspective view of the embodiment depictedin FIG. 1 with one of the plug assemblies omitted.

FIG. 4 illustrates a partially exploded perspective view of theembodiment depicted in FIG. 3.

FIG. 5 illustrates an elevated front view of the embodiment depicted inFIG. 3.

FIG. 6 illustrates an elevated side view of the sectional taken alongline 6-6 in FIG. 2.

FIG. 7 illustrates a perspective view of the embodiment depicted in FIG.6.

FIG. 8 illustrates a simplified perspective view of the embodimentdepicted in FIG. 7.

FIG. 9 illustrates a partially exploded perspective view of theembodiment depicted in FIG. 8.

FIG. 10 illustrates another perspective view of the embodiment depictedin FIG. 9.

FIG. 11 illustrates another perspective view of the embodiment depictedin FIG. 8.

FIG. 12 illustrates an enlarged perspective view of the embodimentdepicted in FIG. 2.

FIG. 13 illustrates a perspective view of the sectional taken along line13-13 in FIG. 2.

FIG. 14 illustrates a perspective view of the sectional taken along line14-14 in FIG. 2.

FIG. 15 illustrates a perspective view of the sectional taken along line15-15 in FIG. 2.

FIG. 16A illustrates a perspective view of another embodiment of areceptacle assembly.

FIG. 16B illustrates an enlarged perspective view of the embodimentdepicted in FIG. 16A.

FIG. 17A illustrates a perspective view of the sectional taken alongline 17-17 in FIG. 16A.

FIG. 17B illustrates an elevated front view of the embodiment depictedin FIG. 17A.

FIG. 18 illustrates a perspective view of the sectional taken along line18-18 in FIG. 2.

FIG. 19 illustrates a simplified elevated front view of the embodimentdepicted in FIG. 18.

FIG. 20 illustrates a partial perspective view of an embodiment of areceptacle assembly.

FIG. 21 illustrates another perspective view of the embodiment depictedin FIG. 20.

FIG. 22 illustrates another perspective view of the embodiment depictedin FIG. 20.

DETAILED DESCRIPTION

The detailed description that follows describes exemplary embodimentsand is not intended to be limited to the expressly disclosedcombination(s). Therefore, unless otherwise noted, features disclosedherein may be combined together to form additional combinations thatwere not otherwise shown for purposes of brevity. In addition, thedepicted features may be used alone or in combination with a subset ofthe other depicted features so as to provide functionality that isappropriate for the corresponding application. Thus, the depictedembodiments are not intended to be limiting unless otherwise noted.

Turning to the Figs., a connector assembly 10 is mounted on a circuitboard 5. The connector assembly includes a cage 30 and has ports 12 thatare configured to receive plug assemblies 90.

As is known, a plug assembly can include a cable 93 attached to a body92 and the depicted embodiment includes a latch 91 that is configured toallow a latch system to releasably engage the receptacle assembly 10.Alternative embodiments of a plug assembly could include a body thatdoes not have a cable attached to it (such as embodiments that providefor optical connectors that can plug into the plug assembly). The body92 protects a paddle card 95 that can have pads on a 0.65 or 0.60 pitchand the paddle card 95 is part of the interface between the plugassembly 90 and the receptacle assembly 10. The depicted body 92includes a surface 94 that includes cooling grooves 96 that extendsubstantially the length of the body that is intended to be insertedinto the port 12 and in an embodiment extend along the top surface to anend 92 a that is past the front 60 a of the projection 60. The coolinggrooves 96 allow air to flow through the port 12 when the plug assembly90 is inserted into the port 12 and substantially improves coolingefficiency compared to prior art designs as the air flow is able todirectly cool the plug assembly 90.

The receptacle assembly 10 includes a top wall 31 a, two side walls 31 band a rear wall 31 c. A bottom wall 31 d can also be provided to improveshielding performance. A housing 50 is positioned in the cage andsupports a wafer array 40. The housing 50 includes a projection 60 and acard slot 62 is provided in the projection 60. The card slot 62 includesa biasing element 68 that is configured to engage the paddle card 95 andbias the paddle card 95 to one side of the card slot 62. This allows forcontrol of the paddle card 95 vis-a-vis the card slot and removes arange of tolerances that would otherwise be associated with the locationof the pads on the paddle card 95 versus the location of contactsprovided in the card slot 62. The housing 50, which can be formed of aninsulative resin, further includes air channels 52 that allow foradditional cooling and can have a back support 54 that snaps onto thehousing 50 and helps secure the wafer array 40 in position.

As is known, the wafer array 40 includes a plurality of wafers 41 andeach wafer 41 supports a plurality of terminals that each can have atail 42 and a contact 44. The contacts 44 are positioned on in the cardslot 62 and typically will be arranged so that some contacts arepositioned on opposing sides of the card slot 62. To improveperformance, short ribs 67 separate the signal terminals that form adifferential pair 45 while long ribs are positioned between the signalterminal and the corresponding ground terminals. As the contacts 44 arepositioned in a single row on a constant pitch, the short ribs 67provide electrical isolation and protection between signal terminalswhile the long ribs 65 increase the dielectric contact between thesignal terminals and the ground terminal compared to the dielectricconstant associated with the signal terminals so as to providepreferential coupling between the differential pair (e.g., even thoughthe terminals are on a constant pitch, more energy is carried in thedifferential coupling than symmetry would suggest). In other words, theribs 65, 67 form grooves that help protect the contacts 44 and thesignal terminals are aligned with a notch 69 formed in the card slot 62that helps lower the dielectric constant near the signal terminalcontacts.

The cage includes a front portion 32 that can provide structure supportfor the rest of the cage 30 and the front portion 32, which can includeshoulders 38 that extend from the bottom wall 31 d, can support an EMIgasket 32 a that can be positioned in the ports and that helps minimizeEMI radiation. Light pipes 29 can be provided (they are shown as beingtransparent like in the Figs. as they often are transparent) andtypically would be configured to direct light from the supportingcircuit board toward a front face 11 a, usually between the two ports.

To help define the ports 12, a central support 21 is provided. Thecentral support 21 can be formed of a top wall 21 a and a bottom wall 21b that are supported by the sides 31 b and help define a bottom or topof a port, respectively. A central duct 26 is defined by the centralsupport 21. The top and bottom walls 21 a, 21 b can include notches 23to further allow airflow into the ports 12. An insert 15 can bepositioned in the central support 21. The insert 15 includes a frontwall 16 with front apertures 16 a that allow air to flow through thefront wall 16 and further allows for indicators that use light pipes toilluminate the corresponding area.

The connector assembly also includes a middle wall 70 that has middlearray 72 with middle apertures 72 a and further includes apertures 72 bpositioned in the top port 12 and includes apertures 72 c positioned inthe bottom port 12. The apertures 72 a, 72 b, 72 c allow air to flowpast the middle wall 70 while still providing desirable EMI protection.The middle wall 70 has cutouts 73 that allow the light pipes 29 toextend past the middle wall 70. Thus the depicted design allows for theuse of light pipes while still providing improved cooling capabilities.

Rear apertures 34 a allow air to flow past the rear wall 31 c. Thehousing 50 is designed so that there is sufficient room on the side ofthe housing 50 so that air can flow past from the middle wall 70 to therear wall 31 c. As can be appreciated, therefore, the connector assembly10 is configured to allow for substantial air flow to pass from thefront face 11 a to a rear face 11 b (or in the opposite direction).Specifically, if air is flowing from the front face 11 a to the rearface 11 b then an insert 15 is configured to allow air to flow throughthe front wall 16, air flows through the central duct 26, then through amiddle wall 70, past the housing 50 and finally out rear wall 31 c.

As can be appreciated, a card slot is disclosed in the embodimentsdepicted that provides terminals at a 0.60 or 0.65 mm pitch. To providefor the necessary tolerances, the biasing element 68 is provided in thecard slot and the biasing element 68 helps ensure the location of oneside of the paddle card is known (one side is biased against one side ofthe card slot). This reduces the tolerance stack-up such that a 0.6 mmpitch connector is possible with a conventional paddle card based matingconnector. Compared to prior art designs this provides a furtherimprovement over biasing the entire plug connector as it has beendetermined that there is the potential for tolerance stack-up of thelocation of the paddle card 95 within the plug connector 90. Thedepicted embodiment, however, eliminates that form of tolerance stack-upas an edge 95 a of the paddle card 95 becomes a datum. The tolerancescan be further improved if the edge 95 a of the paddle card 95 is usedto align pads 97 that are positioned on the paddle card 95. Otherwise,the standard construction techniques used to form paddle cards wouldresult in a tolerance stack-up that would prevent 0.6 mm pitch terminalfrom working in a reliable fashion.

It should be noted that if the terminals are on a larger pitch (such as0.7 or more) then the biasing element can be omitted. The connectordesign still provides desirable cooling properties for what is otherwisea compact package and the cooling features can be incorporated intoconnectors regardless of the pitch of the terminals.

The cable assembly need not provide the cooling grooves in allsituations. If, for example, the cable assembly is a passive device thenthere will be little need for cooling and the cooling grooves can beomitted.

The disclosure provided herein describes features in terms of preferredand exemplary embodiments thereof. Numerous other embodiments,modifications and variations within the scope and spirit of the appendedclaims will occur to persons of ordinary skill in the art from a reviewof this disclosure.

I claim:
 1. A plug connector, comprising: a housing having a top surfaceand a bottom surface and a front end, the housing being formed of athermally conductive material; and a paddle card positioned in thehousing, the paddle card extending toward a front end of the plugconnector, wherein one of the top surface and the bottom surface hascooling grooves extending along a length of the plug connector to form agrooved surface, the grooved surface having troughs in the surface ofthe housing formed by the cooling grooves, the cooling groovesconfigured, in operation, to allow air to flow along the grooved surfaceof the housing toward the front end when the housing is inserted into areceptacle port.
 2. The plug connector of claim 1, wherein the paddlecard has contact pads on a 0.6 mm pitch and the contact pads are alignedwith a side of the paddle card.
 3. The plug connector of claim 1,wherein the cooling grooves extend along the entire portion of thehousing.
 4. A connector system, comprising: a receptacle including acage that defines a port and a housing positioned in the cage, the cagehaving a front face and a rear wall, the housing providing a card slotaligned with the port, the card slot including a plurality of grooves,wherein the housing supports a first plurality of terminals that havecontacts positioned in the grooves; and a first plug connectorpositioned in the port and having a paddle card with pads that engagesthe contacts, the first plug connector including a body with a pluralityof cooling grooves that extend along a length of the body to form agrooved surface, the grooved surface having troughs in the surface ofthe body formed by the cooling grooves, the cooling grooves configuredto allow air to flow through the connector from the front face towardthe rear wall so as to help directly cool the first plug connector. 5.The connector system of claim 4, wherein the terminals are on a 0.6 mmpitch.
 6. The connector system of claim 4, wherein the port is a firstport and the receptacle includes a second port positioned above thefirst port, wherein the card slot is a first card slot, the housingfurther providing a second plurality of terminals with contactspositioned in a second card slot aligned with the second port, thesecond card slot having grooves that help protect the contactspositioned therein and a second plug connector with a body positioned inthe second port, the second plug connector having a paddle card thatengages the contacts positioned in the second card slot, wherein thebody of the second plug connector includes cooling groves that extendalong a length of the body of the second plug connector.